Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Carbon aerogels are highly porous solids that are extremely lightweight. Carbon aerogels have a fully adjustable three-dimensional structure and can provide high surface areas. The addition of dopants can also tune the aerogel's electrical, thermal, and mechanical properties.
Carbon aerogels can be used in a variety of applications, including but not limited to insulation, conduction, convection and radiation of heat, and manufacture of batteries and supercapacitors, electrocatalysis, capacitative deionization, oil spill controllers, and solar energy collectors.
Current methods for producing carbon aerogel include using resorcinol and formaldehyde as starting materials. In these methods, resorcinol and formaldehyde may be reacted in the presence of a basic catalyst, and the subsequent product can be supercritically dried in carbon dioxide to produce an organic aerogel. The organic aerogel can then be pyrolyzed under high temperatures in the presence of an inert gas to produce carbon aerogel. One of the disadvantages of this method is the need for a basic catalyst. If the catalyst concentration is relatively high, the gel may undergo significant contraction during both supercritical drying and carbonization, thereby increasing the difficulty in obtaining carbon aerogel having a low weight density. On the other hand, if the catalyst concentration is relatively low, the gel may not be formed. In addition, the method is complicated and expensive to perform, and difficult to control, particularly on a large scale. The method also requires a long preparation period and involves expensive starting materials. Despite the promising market applications of carbon aerogel, market acceptance and industrialization of carbon aerogel have been hindered because of the high cost and low yield obtained from the current methods of producing carbon aerogel. Therefore, it will be desirable to provide methods and systems for producing carbon aerogels that can at least ameliorate or overcome these disadvantages.